Bag-opening machine



Dec. 12, 1939. A, McCALLUM 2,183,081

BAG-OPENING MACHINE Filed July 11, 1938 5 Sheets-Sheet, l

Dec. 12, 1939. I w A. MQCALLUM 2,183,081

BAG-OPENING MACHINE Filed July 11, 1938 I 5 Sheets-Sheet 2 iDec. 12, 1939.

A. M CALLUM BAG-OPENiNG MACHINE Filed July 11, 1938 3 Sheds-Sheet 3 l-Ll I LU Patented Dec. 12, 1939 v UNITED STATES PATENT ornce BAG-OPENING MACHINE Arthur McCallum. New Brunswick, N. J., assignor to Flako Products Corporation, New Brunswick, N. J., a corporation of New Jersey Application July 11, 1938, Serial No. 218,686

16 Claims.

This invention relates to improvements in bagopening machines.

One object of the invention is to provide a bag-opening machine of comparatively simple construction, but which will operate with maximum efllciency.

Another object of the invention is to provide a bag-opening machine which, in opening the bag, will open it fully in the sense that the entire area of the bottom of the bag will be opened fiat and, consequently, the bag will be fully opened throughout its entire depth.

A still further object of the invention consists in the provision of means for facilitating partially opening the bag before it is engaged by the opening plunger and means for facilitating removal of the bag, after it is opened, from said opening plunger.

Specifically, the invention contemplates a bagopening machine provided with a reciprocatory plunger having a cross-section corresponding to that of a fully opened bag, and means normally positioned in advance of or projecting beyond the plunger for spreading the bag open to permit the plunger proper to enter the mouth of the bag. The machine comprises means for deliv-,- ering a blast of air laterally of these initial spreading members sothat, as the mouth of the bag is moved toward said members, this blast of air will tend to open the mouth of the bag,

whereupon the bag is inserted on said spreader members. These spreader members converge toward each other in advance of the plunger but, upon an advance movement of the plunger, the same enters between the'spreader members and, in doing so, spreads them, together with the bag, open. Thus, the plunger which, as before mentioned, is of a cross-section corresponding to that of a fully opened bag, may readily be inserted the full depth of the bag, the end of the plunger preferably advancing ultimately beyond the spreader members, so as to insure fully opening or flattening out the bottom of the bag.

With these and other objects in View, the invention consists in certain details of construction and combinations and arrangements of parts, all as will hereinafter be more fully described, and the novel features thereof particularly pointed out in the appended claims.

In the accompanying drawings- Figure 1 is a side elevational view of a bagopening machine embodying the present improvements;

Fig. 2 is a front elevational view of the machine;

Fig. 3 is a vertical sectional view taken trans-- versely of the machine, the bag, spreader members and the lower portion of the plunger being shown in section;

Fig. 4 is a vertical sectional view taken at right 5 angles to Fig. 3, on the line 4-4 of Fig. 3; v

Fig. 5 is a vertical sectional view, similar to Fig. 3, illustrating the plunger retracted and the bag as about to be placed on the spreader members; 10

Fig. 6 is a view similar to Fig. 5 showing the plunger partially advanced, as distinguished from the fully advanced position illustrated in Figs. 3

and 4; 7

line 7-1 of Fig. 6;

Fig. 8 is a perspective view of the bag-engaging portion of the plunger;

Fig. 9 is a detail perspective view illustrating the mounting of the spreader members; 20

Fig. 10 is a horizontal sectional view on the line Ill-J0 of Fig. 3;

Fig. 11 is a vertical elevational view illustrating in detail the pivotal mounting of the springpressed spreader members. 25

In the preferred embodiment of the apparatus illustrated in the present instance, the machine comprises a bag-opening plunger consisting of a reciprocatory section l5 telescopically engaging a fixed section It, the reciprocatory section 30 being slidably mounted in a bracket I at the upper portion of standards l8 of a main supporting frame i9. Both plunger sections l5, ii, are of tubular formation and air, under pressure, is adapted to be supplied thereto from a fan 20 35 mounted on a suitable support 2i, said fan being provided for purposes which will hereinafter be described. The lower extremity of the sliding section i5 of the plunger, which is adapted to enter the bag to be opened, is of polygonal crosssection, being illustrated as square or rectangular in the present instance, and the end face of the plunger is provided with a plurality of openings 22 to permit the escape of air supplied by blower 2t.

Slidably carried on the polygonal portion of 45 the plunger is a collar 23 formed with ways 23 adapted to engage with guides 25 on the side walls of a housing 26 mounted on a lateral extension 2'! on the standards it. This collar 23 is, under certain circumstances, adapted to move in unison with the reciprocating plunger while, under other circumstances, it is adapted to remain stationary, so that the plunger can move with respect thereto. For this purpose, the collar is provided with a plurality of spring-pressed frict on elements 28 protruding from its inner surface and adapted to engage against the surface of the plunger, the frictional engagement being such as to cause the collar to move with the plunger in the absence of additional means tending to restrain movement of the collar. Referring, particularly, to Figs. 3 to 6, it will be noted that the housing 26 is formed with inwardly extending shoulders 29 and 30 at its lower and upper ends, which limit the movement of the collar 23. In other words; the collar 23 is free to move in unison with the plunger l5 from the po nt where the collar will engage shoulder 30 to the point where the collar comes into engagement with shoulder 29. Thus, during the retractive orupward movement of the plunger, the collar will move in unison therewith until it engages shoulder 30, whereupon movement of the collar will be arrested, while the retraction of the plunger continues. Likewise, on the advance or downward movement of the plunger, the collar will move in un son with the plunger until it engages with shoulder 29, whereupon movement of said collar will be arrested while the plunger continues to advance or move downwardly with respect to the housing and collar.

For the purpose of spreading the sides of a bag open to an extent such as will permit the polygonal plunger to enter the same, so-called spreader members 3|, 32, are provided on the collar 23. With the plunger in its retracted or upper position, spreader members 3|, 32, project beyond the plunger end and converge toward one another, as illustrated in Figs. 5 and 9. The spreader members are merely yieidingly urged toward one another and can be spread apart by the plunger end entering therebetween. For instance, spreader member 3! may be rigidly secured to the collar, but possesses sufficient resiliency to permit it to flex back and forth when the plunger moves into and out of the space between the two Spreaders. If desired, the other spreader member 32 may be hinged on the collar 23, such construction being shown in detail in Fig. 11, where the spreader is hinged on a pin 38 and is yieldingly urged toward the other spreader by a spring 3 Normally, the bags to be opened are completely collapsed when delivered to the bag-opening machine and, to facilitate insertion of the spreader members 30, 32, into the mouth of the bag, a conduit 35 is d sposed in the side of housing 26 in position to direct a blast of air, indicated at 36, past the advance edges of the spreader mem- E bers, so that, as the operator moves the mouth end of the bag toward the spreader members, this blast of air will tend to open the bag mouth, as illustrated in Fig. 5. The bag is then placed on the spreader members or the latter may be said to be inserted in the bag, whereupon downward motion is imparted to the reciprocatory section of the plunger. This is done with the parts in the positions in which they are illustrated in Fig. 5 and, as the plunger moves downwardly, the carrier collar 23 s likewise carried downwardly, so that the spreader members 3 i, 32, move farther into the bag until the collar 23 comes into engagement with stop 29 at the lower end of housing 26. When this occurs, the spreader members 3!, 32, are held against further downward movement, but the plunger continues to advance with respect thereto, so that the spreader members are moved apart or away from each other, opening the bag to its full cross-section, as shown in Fig. 6. The plunger then continu s its advance movement to a point sumciently far beyond the free edges of the spreader members as to engage against the bottom of the bag and press it flat on the base 31 of the frame M, as shown in Figs. 3 and 4. Thus, the bag is fully opened with its bottom perfectly flat. To prevent the bag slipping off of or with respect to the spreader members, as the plunger advances beyond the latter, means are provided for releasably retaining the bag on said spreader members. For instance, the bag may be held on the spreader members by spring-pressed pins 38, slidably mounted in one end of a lever 39, pivoted at 40 on the collar 23. The other end of said lever projects upwardly beyond the collar and carries a cam roller 4| adapted to be engaged by a cam 42 on the exterior of the plunger. Thus, as the plunger is advanced downwardly, cam 42 moves from the position illustrated in Fig. 5 to a point where it engages cam roller 4! and rocks lever 39 to press the friction elements or pins 38 against the bag then on the spreader members.

The bag having been fully opened, as just described, the plunger is retracted, and as it moves upwardly, collar 23 is carried along with it until said collar engages against stop 30, whereupon movement of the collar ceases while the upward movement of the plunger continues. This continued upward movement of the plunger causes cam 42 to become disengaged from cam roller II on lever 39 to relieve the pressure of the friction elements 38 on the side of the bag. As the section l5 of the plunger continues its upward movement, it will be appreciated that the pressure of the air supplied to the plunger by fan 20 will increase, due to the gradually decreasing length of the plunger and, as the plunger approaches its upper-limit of movement, this blast of air will possess sufiicient force or pressure to dislodge the opened bag from the spreaders 3i, 32, the air issuing from the perforations 22, previously described, in the end wall of the plunger.

The mechanism for imparting the reciprocatory motion to the traveling section I5 of the plunger may consist of bars 43 pivoted to a collar 46 fixed on plunger section i5 and also pivoted intermediate their ends on links which, in turn, are pivotally mounted at it? on the standard l8. Spanning the space between the two bars 43, is a cross pin il, to which one end of a connecting rod $8 is pivoted, the lower end of said connecting rod being attached to a cranl: d9 on a shaft 56 driven from a motor Hi. The electrical connections for actuating motor 5i and. the motor 20 of fan 28 are shown diagrammatically, one lead of the fan 80 being connected by line 52 to the main feed line 53, while the other lead of the fan is connected by line 56, through rheostat E35 and line 56, to the other main feed line 57!. The main feed line 5? extends to one lead of the motor 5! and the other main feed line is connected to a foot-pedal-actuated switch 58 which, in turn, is connected by line 59 to the other lead of motor 513. With this arrangement, fan 28 can be driven at any desired speed to furnish a continuous supply of air to the plunger and the conduit 35. but the reciprocation of the movable section I5 of the plunger is controlled to intermittently actuate the same by the operator closing the circuit through the pedal switch 53.

It will thus be seen that the present machine is of comparative y simple and inexpensive construct on but, at the same time, capable of emcient operation for the purpose of fully opening the bags, even to the extent of spreading, so to (iii the end of said member and normally converging speak, the bottom or the bag perfectly flat, so that there will be no difliculty whatever in properly filling the bag with the commodity or material to be packaged therein.- This is primarily due to the fact that the so-called spreader members present the bag for reception of the polygonal plunger which is of a cross-sectional area substantally corresponding to the surface of the 'bag bottom when the latter is fully opened. The efiiciency of the machine is also increased by reason of the fact that the bag is firmly retained on the spreader members 3t, 32, during the time the plunger passes beyond said members while, at the same time, these bag-retaining means releasably'engage the bag in the sense that, as the movable section of the plunger is retracted and the over-all length of the plunger decreased, the pressure of the air blast in the plunger is bu lt up to a point to overcome said bag-retaining means and displace the bag independently of any manual operation by the machine attendant.

What I claim is:

I. In a bag-opening machine, a reciprocatory tubular member movable into the mouth of the bag, said member being of a cross-section substantlally corresponding to that of the bag when the latter is fully opened, a pair of laterally movable spreader elements slidably supported on and positioned in advance of the tubular member adapted to enter the bag in advance of said tubular member, said elements normally converging toward each other in the direction of their leading edge, means yieldingly holding said spreader elements and tubular member against relative longitudinal movement, and means restraining movement of said spreader elements during portions of the movements of said member.

2. In a bag-opening machine, a slidable tubular member and spreader elements frictionally supported at opposite sides of said member and movable longitudinally of said member, said spreader elements converging toward each other in advance of said member but movable laterally away from each other by movement of the said tubular member therebetween.

3. In a bag-opening machine, a slidable tubular member having a cross-section corresponding to that of the bag when the latter is fully opened, and the end face of said member corresponding to the surface of the bag bottom, and spreader elements at opposite sides of said member and movable longitudinally of said member, said spreader elements converging toward each other in advance of said member but movable laterally away from each other by movement of the said tubular member therebetween, said spreader elements being yieldingly urged toward each other, and means frictionally engaging said tubular member for yieldingly restraining relative movement between said elements and the tubular member.

being movable longitudinally relatively of said member, means yield ngly resisting movement of said spreader means relative to said member, and means limiting movement of said spreader means with respect to said member.

5. In a bag-opening machine, a reciprocatory member, spreader elements projecting beyond toward each other, said member being movable relatively to said elements to spread the latter apart and means frictionally engaging said member for yieldingly restraining relative movement of said elements and said member.

6. In a bag-opening machine, a reciprocatory member, spreader elements projecting beyond said member and converging toward each other, said elements being frictionally supported on and normally movable with said member, and means for holding said elements against movement whereby said member can move relative to and between said elements to spread the latter apart.

7. In a bag-opening machine, a reciprocatory tubular member composed of telescoping sections and having an end face substantially corresponding to the bottom surface of a fully opened bag, means for reciprocating one of said sections to extend and collapse said member, means for supplying air under pressure to said member, converging spreader elements slidably supported on said member and projecting beyond said end thereof, said member and elements being movable relatively to each other to position said member between said elements and spread the latter apart, the sections of said member being partially collapsed endwise by their telescopic movement as said member is withdrawn from between said elements.

8. In a bag-opening machinaa reciprocatory plunger having an end face substantially corresponding to the bottom surface of a fully opened bag, spreader elements projecting beyond said end of the plunger, said elements being carried by the plunger and yieldingly held in converging relationship, friction elements interposed be tween said plunger and spreader elements yieldingly holding the latter against movement relatively to said plunger, and stops limiting move ment of the spreader elements whereby said plunger can be advanced and retracted with respect to the spreader elements to intermittently spread the latter apart.

9. In a bag-opening machine, a tubular plunger formed of telescoping sections, means for advancing and retracting one section relatively to the other, laterally movable spreader members slidably supported on the movable section of the plunger, said movable section also being movable relatively to said spreader members, and means for supplying air under pressure to said tubular plunger.

iii. In a bag-opening machine, a reciprocatory plunger,. plunger said plunger and members being movable relatively to each other to advance and retract the plunger between said members and intermittently spread the latter apart, means for releasably retaining a bag on said spreader members, and means operable by the plunger for moving said retaining means toward and from said members.

11. In a bag-opening machine, a reciprocatory plunger, spreader members carried by said plunger, said plunger and spreaders being movable relatively to each other to intermittently spread the latter apart, a pivotally supported bagengaging member movable toward and from one of said spreaders to releasably retain a bag on said spreaders, and means for actuating said bagengaging member.

12. In a bag-opening machine, a reciprocatory plunger, a collar yieldingly supported on said plunger, means spaced longitudinally of the spreader members carried by saidplunger for resisting movement of the collar with the plunger, spreader members carried by said collar movable away from each other by movement of the plunger between the same when movement of said collar in one direction is arrested, and means carried by said collar and operable by said plunger for releasably retaining a bag on said spreader members.

13. In a baa-opening machine, a reciprocatory plunger, a collar yleldingly supported on said plunger, means spaced longitudinally of the plunger for resisting movement of the collar with the plunger, spreader members carried by said collar movable away from each other by movement of the plunger between the same when movement of said collar in one direction is arrested, a lever pivotally mounted on said collar, one end of said lever being movable toward and from one of said spreaders, and means on said plunger for actuating said lever.

14. In a bag-opening machine, a plunger formed of telescoping sections, a pair of spreader members slidably supported on but movable with said plunger, means for reciprocating one of said plunger sections to advance and retract the same relatively to the other section, means Eor limiting movement of said spreader members whereby said movable plunger section is moved relatively and between said members, said plunger section being movable at least to the free extremities of said members.

15. In a bag-opening machine, a plunger formed of telescoping sections, means for reciprocating one section longitudinally of the other, a collar surrounding said movable section, triction elements interposed between said collar and said section to yieldlngly restrain movement of the collar on the plunger, stops engageable with the collar for limiting movement of the latter with said plunger, and oppositely disposed spreader members on said collar projecting beyond the end of said plunger, the projecting portions of said members normally converging toward each other, said reciprccatory plunger section being movable between said spreader members to at least the free extremities thereof. 16. In a bag-opening machine, a plunger formed of telescoping sections, means for reciprocating one section longitudinally of. the other, a collar surrounding said movable section, friction elements interposed between said collar and said section to yieldingly restrain movement of the collar on the plunger, stops engageable with the collar for limiting movement of the latter with said plunger, and oppositely disposed spreader members on said collar projecting beyond the end of said plunger, the projecting portions of said members normally converging toward each other, said reciprocatory plunger section being movable between said spreader members to at least the free extremities thereof, and means for directing a blast of air laterally of the free extremities of said members.

McCAlLUM. 

